The National Broadband Network Company (NBN) is trialling cheaper and less intrusive technology to take fibre to the driveway of homes, in a bid to divert criticism the mixed rollout is creating a digital divide in Australia.

Key points:

First driveway connection under FTTC has been activated at Coburg in Melbourne

NBN Co is under increasing pressure over network's rollout

FTTC technology expected to ensure every home will receive broadband by 2020

The technology known as fibre-to-the-curb (FTTC) is a less costly alternative to fibre-to-the-premises (FTTP) connections, where trenches often need to be dug, or the NBN's controversial fibre-to-the-node (FTTN) which requires mains powers on street corners.

The first driveway connection under FTTC — which the NBN describes as "ground-breaking network technology" — has just been activated at Coburg in Melbourne's northern suburbs.

The trial of the new technology comes as the NBN Co is under increasing pressure over network's rollout, in particular complaints about slow speeds and that the mix of technology means some streets or regions are divided between FTTN and FTTP broadband.

NBN chief executive Bill Morrow revealed the new fibre to the driveway technology ahead of an investigation by the ABC's Four Corners showing the mixed technology nature of the rollout was creating a digital divide in some communities.

"We believe FTTC will become another vital tool in the mix of technologies we're using to deliver the NBN," Mr Morrow said.

"Our huge country makes deploying the NBN extraordinarily complex, so having flexibility in terms of the technology we deploy in the field is incredibly important."

In a statement, the NBN Co said delivering new fibre technology to the driveway or property boundary via FTTC would mean substantial cost and time savings.

The NBN estimates a FTTC connection will cost $2,900 per premises compared to $4,400 for a direct household connection under FTTP.

As costs of the overall NBN rollout continue to mount, the NBN Co has, for the first time, revealed the 10 most expensive FTTP connections in each state and territory.

Tasmania ranks as the most expensive state for NBN connections, with high costs for select properties in Invermay ($86,533), Kingston ($55,766), Relbia ($44,157) and Riverside ($39,166).

In New South Wales, the NBN is facing $41,304 to connect a commercial business at Strathfield in Sydney's inner-west, while another business at Ballarat in central Victoria would cost $51,464 to activate.

While the list provided only lists the 10 most expensive spots in each state, it emphasises there is a "huge additional number" that have not been listed.

Commenting on the NBN's blog, Mr Morrow described the first trial of the fibre-to-the-curb technology as "another proud moment" for the NBN that would ensure every home will receive universal broadband by 2020.

However, Mr Morrow defended the rollout and the controversial mix of technology mandated by the Turnbull Government when it took office.

"Of course, I understand why some people come out with glib catchphrases like, 'Do it once, do it right, do it by fibre'," Mr Morrow said.